Things to add to our list, from spectator comments:
20) Big step for kids. ~1.5ft tall, 8ft long, 2ft wide. Assuming a child takes up 1.5x1ft each, this would allow 10 kids to see!
21) Live tournament brackets. As basic as a big piece of posterboard and sharpie, as fancy as the tv screen showing whole brackets or even a live website everyone can check (gives more sponsor advertising opportunities too!).